Coupling system and method of use thereof

ABSTRACT

A coupling system for a vehicle such as an articulated lorry and method of use thereof is provided. The articulated lorry includes at least a tractor unit and a trailer unit. The tractor unit has first coupling means provided on a fifth wheel which engages with second coupling means typically in the form of a kingpin on the trailer unit. The fifth wheel coupling means and the kingpin have one or more pneumatic and/or electrical supply lines provided therein which engage upon mechanical engagement of the fifth wheel coupling means and kingpin, thereby allowing pneumatic and/or electrical supply between said tractor unit and said trailer unit and/or vice versa. One of the fifth wheel coupling means or kingpin is provided with one or more annular protrusions on a coupling surface and the other is provided with complementary annular channels on a coupling surface. The annular protrusions engage with the annular channels upon mechanical engagement of the tractor unit and trailer unit to affect the connection of at least one of said supply lines simultaneously to mechanical coupling of the tractor and trailer units.

This invention relates to a coupling system and method of use thereof,and particularly to a coupling system for facilitating the mechanical,electrical and/or pneumatic coupling and uncoupling between at leastfirst and second units.

Although this application refers almost exclusively to a coupling systemfor a cab unit and a trailer unit of an articulated lorry, it will beappreciated by persons skilled in the art that the coupling system couldbe used between any two or more units where mechanical, electricaland/or pneumatic coupling and uncoupling is required. For example, thecoupling system could be used between a car and caravan, tractor andtrailer or the like.

A lorry typically comprises a cab and a trailer which can bemechanically coupled/uncoupled. The cab supplies the trailer withelectrical and pneumatic services in order to provide the trailer withbrakes, lights and other facilities.

Conventionally, cabs comprise a fifth wheel unit which provides couplingmeans thereon to allow coupling with coupling means, typically in theform of a kingpin, provided on a trailer. Electrical and/or pneumaticsupply lines are provided on or adjacent the fifth wheel for connectionwith supply lines on the trailer, thereby allowing the supply ofelectrical and/or pneumatic services from the cab to the trailer.

The kingpin is normally coupled and uncoupled from the cab via a manualprocedure, which involves the driver of the lorry leaving their cab andphysically making all the necessary mechanical, electrical and/orpneumatic connections by hand. The driver has to then secure all theseconnections using tools to ensure that the trailer does not becomemechanically disconnected or lose pneumatic and/or electrical powerduring travel.

A disadvantage with conventional coupling procedures is that the driveris required to leave his or her cab to perform the necessary operations,and in certain countries where coupling/uncoupling procedures occur inremote locations or at service stations, this can leave the drivervulnerable to attack and/or robbery. In addition, once the driver leavestheir cab unit, they are at risk of being hit by another vehicle,particularly when the driver is required to couple/uncouple the units ina busy traffic area such as on a motorway hard shoulder. A furtherdisadvantage of the present coupling procedure is that the parts thedriver is connecting are typically covered in grease, oil and dirt andthe driver often has to kneel or lie on the road surface to make thenecessary connections. This inevitably results in the driver becomingdirty which is undesirable to the driver.

There are a number of safety issues associated with conventionalcoupling procedures which require improvement. One of the major safetyproblems is that the driver may not secure the coupling means betweenthe trailer and the cab sufficiently. For example, if the coupling meansare not secure, continual movement of the same caused by jolts and bumpsduring transit may result in accidental uncoupling.

In the event of a fire in the cab or trailer, the driver is likely toabandon the cab and trailer since uncoupling the same would take toolong and thus put the driver's life in danger. If the fire then spreads,both the cab and the trailer unit, with any goods carried in the same,would be destroyed and would result in large financial loss to thecompany and/or insurance company.

Coupling systems have been designed to allow coupling of the cab andtrailer to be operated by the driver from within the cab. These systemstypically include the steps of the coupling means on the fifth wheel andthe kingpin being mechanically connected prior to connection of thesupply lines. Separate connection of the supply lines and mechanicalcoupling increases the time taken for the coupling and uncouplingprocedures to be completed, thus having the same problems as mentionedabove. The coupling mechanisms associated with such systems are oftencomplicated and need a large number of components, thereby making thesystems prohibitively expensive and more difficult to keep in goodrepair.

One known system is described in EP816211 and attempts to overcome theabovementioned problems by providing the supply lines within the cab andtrailer coupling units rather than separately, thereby allowingmechanical coupling and supply line coupling to occur simultaneously.The document discloses a trailer kingpin, and a fifth wheel couplingunit on a cab having a movable part located in the coupling unit. Adrive unit in the fifth wheel coupling unit drives the movable part intothe kingpin to establish coupling therebetween, and is able to retractthe movable part when uncoupling of the cab and trailer is required. Thekingpin then rotates to allow positioning of the kingpin relative to themovable part of the fifth wheel coupling unit to complete the couplingprocess. Problems associated with this type of coupling system are thatthere are no alignment means. Due to the number of connection componentsin the coupling units, the components have to be cast or moulded andassembled separately and this can be time consuming and expensive. Inaddition, due to the fragility of the connection components and the factthat all these components are rotated during coupling, the componentsare susceptible to high levels of fatigue stress and are easily damaged.

The object of the present invention is to provide an improved couplingsystem which overcomes the abovementioned problems.

According to a first aspect of the present invention there is provided acoupling system for a vehicle for coupling at least a tractor unit to atrailer unit, said tractor unit having first coupling means which engagewith complementary second coupling means on said trailer unit, saidfirst and second coupling means having one or more service supply linesprovided therein and said service supply lines of said first and secondcoupling means engaging upon mechanical engagement of said first andsecond coupling means, thereby allowing the supply of services from saidtractor unit to said trailer unit and/or vice versa, and characterisedin that one of said first or second coupling means is provided with oneor more annular protrusions on a coupling surface and the other of saidcoupling means is provided with complementary annular channels on acoupling surface, said annular protrusions being received in saidannular channels upon mechanical engagement of said first and secondcoupling means, thereby simultaneously or substantially simultaneouslyallowing the connection and/or communication of at least one of thetractor supply lines with at least one of the trailer supply lines toallow the supply of said service(s) therebetween.

Preferably the coupling system is capable of being operated by a driverwithin the tractor and/or trailer unit.

Preferably three annular protrusion and three annular channels areprovided on the trailer and cab coupling units respectively.

Preferably the coupling means on the tractor and trailer aresubstantially vertically aligned prior to mechanical engagement/supplyline connection. Thus engagement is effected between the two couplingunits on a horizontal plane.

Preferably the tractor and trailer coupling means are unitary members,which allow for the mechanical connection and also electrical and/orpneumatic connection on connection of the service supply lines.

Preferably a plurality of facilities are provided on engagement of thecoupling means. For example, the facilities can include operation ofsupport legs on the first and/or second unit.

Preferably communication and/or connection of one or more pneumaticsupply lines between the tractor and trailer are effected via engagementof the annular protrusions in the annular grooves/channels. Thepneumatic supply lines have openings in the grooves and/or protrusions,typically one opening in each groove and one in each protrusion, whichcommunicate on engagement of the tractor and trailer coupling means.Upon connection, air is able to flow, typically from the pneumaticsupply in the tractor, around the annular grooves and into the openingson the annular protrusions to deliver air to the trailer.

Preferably sealing means, such as O-rings or other conventional sealingmeans can be provided in the annular grooves and/or on the annularprotrusions to allow a sealed passageway to be formed on engagement ofsaid grooves/protrusions.

The annular grooves and protrusions allow for angular freedom betweenthe tractor and trailer units to be accommodated for during engagementand use. In addition, the annular grooves/protrusions can be integrallycast or moulded as part of the coupling means to provide strong couplingdevices, typically made of steel which are not fragile like conventionalcoupling means.

The annular protrusions and/or channels also allow for a small degree ofrotation of the first and second coupling means during normalarticulation of the vehicle, i.e., about a horizontal plane, such aswhen the vehicle goes round corners, so that the sealed passage formedby engagement of the protrusions/channels is not broken/damaged thusallowing the first and second supply pipes connected to the passage tobe in continued connection despite the rotation. The connectiontechnique can be repeated for further supply pipes with further passagesformed as required and thus the need for flexible connection hoses isavoided, as is the need for the same to be manually connected.

Further preferably the coupling means are provided in casing to protectthe same from the weather.

Preferably a quick release switch is provided in the cab and/or trailerunits to enable the uncoupling procedure to be carried out quickly inthe event of an emergency. For example, in the event of fire in thetrailer or cab, the cab can be quickly released from the trailer anddriven a safe distance away from the same to ensure that the fire doesnot spread to the unaffected unit.

Preferably the first unit and/or the second unit is supplied with asignal box which has signalling means to indicate to a user/driver ofthe unit(s) that each or all of the coupling steps have been completedsuccessfully. The signalling means can include any audio or visualsignal such as one or more alarms or one or more lights.

Preferably the signal box, quick release switch and/or further controlmeans for the coupling system are provided with a security means suchthat only certain personnel can operate the system. This prevents orreduces the incidence of theft of the first and/or second unit. Forexample, a pin number can be inserted into the security means before thesignal box, quick release switch and/or further control means are madeoperational. The pin number can be specific to the driver, the companyor can include the number plate of the first and/or second unit or thelike. In addition, the security system can be connected to the vehiclesstarter motor such that the vehicle will not start unless the securitymeans has been disarmed. For example, the pin number may be requiredbefore the brakes of the cab and/or trailer unit are released. Thisfeature is likely to significantly reduce insurance premiums for usersof the present invention since the risk of the vehicles being stolen issignificantly reduced.

The coupling system can be retrofitted to a conventional coupling systemor the tractor and/or trailer units can be fitted with new couplingmeans. This ensures that lorry owners do not have to replace entirefleets of vehicles in order to use the present invention. For example,both the tractor and trailer can be fitted with the coupling units orthe tractor unit can be fitted with a coupling unit and can be used withboth modified and unmodified trailer units.

The pneumatic hoses can be short armoured flexible hoses. Conventionalflexible hoses, which are typically prone to failure, are therefore notrequired. However, it is envisaged that a cab unit having the presentcoupling system retrofitted thereto may retain the existing connectorsto allow connection to conventional trailers if required.

Preferably the electrical connections communicating with the plug andsocket arrangements will either retain the existing coiled cables toprovide flexibility for, i.e., when a multi pin plug connector is used,or use short armoured cables for, i.e., if multiplexing or an opticalconnection is used.

Preferably pneumatic operation of one or more of the support legs of thetrailer unit is controlled remotely from the cab unit.

Further preferably the one or more support legs are provided with alocking means to lock the support legs in an in-use position, where thelegs are in contact with a floor surface, and an out-of-use positionwhere the legs are out of contact with a floor surface.

Preferably the signalling means in the first and/or second unit indicateto a user/driver that the one or more support legs are in an in-useposition or an out-of-use position.

Preferably the first and/or second coupling parts are provided with acover mounted thereon. The cover is typically spring loaded and ismechanically displaced from the coupling part(s) during the couplingprocess, thereby exposing the coupling surfaces, and moves to cover thecoupling part(s) during the uncoupling process.

Preferably the electrical connection between the trailer and tractorunits is achieved by engagement of a plug in one of said coupling meansand a complementary socket in the other of said coupling means. Theelectrical connection between the plug and socket can be via a pluralityof electrical pins and corresponding recesses, electrical pulse signalsof a multiplex system or via fibre optic means.

Preferably the second coupling means of the trailer unit is alignedabove the first coupling means of the tractor unit during the couplingprocedure and linearly reciprocating means are provided to raise orlower one of said coupling means between a coupled position, wherein thecoupling means are engaged, and an uncoupled position wherein thecoupling means are disengaged and spaced apart.

Preferably the linearly reciprocating means includes a pneumaticallyoperated arm.

In a second aspect of the invention there is provided a vehicle having acoupling system for coupling a tractor unit to a trailer unit, saidtractor unit having first coupling means which engage with complementarysecond coupling means on said trailer unit, said first and secondcoupling means having one or more service supply lines provided thereinand said service supply lines of said first and second coupling meansengaging upon mechanical engagement of said first and second couplingmeans, thereby allowing the supply of services from said tractor unit tosaid trailer unit and/or vice versa, and characterised in that one ofsaid first or second coupling means is provided with one or more annularprotrusions on a coupling surface and the other of said coupling meansis provided with complementary annular channels on a coupling surface,said annular protrusions being received in said annular channels uponmechanical engagement of said first and second coupling means, therebysimultaneously or substantially simultaneously allowing the connectionand/or communication of at least one of the tractor supply lines with atleast one of the trailer supply lines to allow the supply of saidservice(s) therebetween.

According to a yet further aspect of the present invention there isprovided a fifth wheel for a tractor unit, said fifth wheel having firstcoupling means which engage with complementary second coupling means ona trailer unit, said first and second coupling means having one or moreservice supply lines provided therein and said service supply lines ofsaid first and second coupling means engaging upon mechanical engagementof said first and second coupling means, thereby allowing the supply ofservices from said tractor unit to said trailer unit and/or vice versa,and characterised in that one of said first or second coupling means isprovided with one or more annular protrusions on a coupling surface andthe other of said coupling means is provided with complementary annularchannels on a coupling surface, said annular protrusions engaging withsaid annular channels upon mechanical engagement of said first andsecond coupling means, thereby simultaneously or substantiallysimultaneously allowing the connection and/or communication of at leastone of the tractor supply lines with at least one of the trailer supplylines to allow the supply of said service(s) therebetween.

According to a further aspect of the present invention there is provideda method of coupling tractor and trailer units together, said methodincluding the steps of positioning said tractor and/or trailer unitsrelative to each other to allow alignment of first coupling means onsaid tractor unit with second coupling means on said trailer unit,actuating movement means on one of said coupling means to allow linearmovement of said one coupling means to the other of said coupling meanswhich is fixedly mounted to couple said means together, andcharacterised that one of said first or second coupling means isprovided with one or more annular protrusions on a coupling surface andthe other of said coupling means is provided with complementary annularchannels on a coupling surface, said annular protrusions engaging withsaid annular channels upon mechanical engagement of said first andsecond coupling means, said engagement of said annular protrusions andgrooves effecting connection and/or communication of at least oneservice supply line between said tractor and trailer unitssimultaneously or substantially simultaneously to the mechanicalcoupling of the tractor and trailer units.

Advantages of the present invention are that the driver of the cab unitor car does not have to leave their vehicle in order to actuate thecoupling and locking mechanisms, thereby reducing the risk to the driverof being attacked or robbed or being hit by another vehicle whilstoutside the cab. In addition, the driver avoids getting cold and wetduring bad weather and ensures that their work clothes are not soiledfrom having to kneel or lie on the ground and actuate the coupling andlocking mechanism manually. This can allow the driver to wear smarter,cleaner clothes and thus improve the public's perception of the driver,the driver's competence and the company the driver works for. The systemis also easy to operate and so users of the system do not need anyspecialised training.

Further advantages of the present invention include the improvedaerodynamic properties of the trailer and cab units by providing theservice supply lines within the mechanical coupling units due toimproved streamlining, which results in the fuel consumption of thevehicle being improved. The cab can be released quickly from the trailersuch that the turnaround time of vehicles at ports and depots isreduced, thus making the turnaround process more efficient and savingthe vehicle owner both time and money. Furthermore, since vehicles withthe coupling system of the invention have safety features not present onconventional vehicles, such as electronic switching of the number platesof the second unit, insurance premiums are likely to be reduced, therebyreducing the expense to the vehicle owner. The present invention canalso be retrofitted to conventional vehicles.

An embodiment of the present invention will now be described withreference to the following Figures wherein:

FIG. 1 is a schematic view of the external appearance of a trailercoupling unit;

FIG. 2 is a simplified cross sectional view of the trailer coupling unitshown in FIG. 1;

FIG. 3A is a simplified cross sectional view of a cab coupling unit;

FIG. 3B is a simplified cross sectional view taken along line B—B ofFIG. 3A;

FIG. 4 is a side view of the cab and trailer coupling units when alignedprior to coupling;

FIG. 5A is schematic representation of the primary locking mechanism ina closed position according to an embodiment of the present invention;

FIG. 5B is a representation of the primary locking mechanism in an openposition according to an embodiment of the present invention;

FIG. 6A is an end view of a trailer electrical plug;

FIG. 6B is an end view of a cab electrical socket;

FIG. 6C is a side view of the cab electrical socket;

FIG. 6D is a detailed cross sectional view of the side of the trailerelectrical plug;

FIG. 6E is a side view of the trailer electrical plug;

FIG. 6F is a simplified side view of an electrical connection accordingto a further embodiment of the present invention;

FIG. 7 is a representation of the jack system which is operable via thepresent invention; and

FIGS. 8A and 8B are simplified representations of the cab and trailercoupling units showing the pneumatic supply.

Referring to the figures, there is shown components of a coupling systemfor a vehicle having a first cab coupling unit and a second trailercoupling unit (hereinafter referred to as cab unit and trailer unitrespectively).

FIG. 1 shows an external view of the trailer unit 102 which is fixedlymounted to a trailer 104. The trailer unit 102 is provided with ahousing 103, coupling surface 106 and annular protrusion surface 108.

FIG. 2 shows the trailer unit 102 having a centrally located electricalplug 116, a passageway 118 for the pneumatic supply and internal annularchannels 104 to provide means for collecting the pneumatic supply from anumber of points before supplying the trailer with pneumatic pressure.The trailer unit is also provided with annular protrusions 110, 112 and114.

Referring to FIGS. 3A & 3B, there is illustrated a cross sectional viewof a cab unit 202 comprising a housing 203, a coupling surface 204, acentrally located electrical socket 206, a pneumatic connector 208 and apneumatic passageway 216.

The cab unit 202 is further provided with annular channels 210, 212 and214. FIG. 2B is a cross sectional view taken along line B—B of FIG. 3and shows the annular channels 210, 212 and 214. A pneumatic passagewayopens into each annular channel, such that pneumatic passageway 216 hasan opening 218 in annular channel 210, and further pneumatic passagewayshave openings 220 and 222 in annular channels 212 and 214 respectively.Only one pneumatic passageway has been shown in the Figures for thepurposes of clarity.

It will be appreciated by persons skilled in the art that the number ofannular channels and/or pneumatic passageways can be varied accordinglydepending on the requirements of the cab and trailer.

During the process of coupling the trailer to the cab, the cab isreversed towards the trailer in the conventional manner until thecoupling surface 204 of the cab unit 202 is aligned with the couplingsurface 106 of the trailer unit 102. This alignment is realised when thetrailer unit 102 contacts surface 224 on the cab units fifth wheel 225,as shown in FIG. 4. (Also shown in plan view in FIG. 5b where trailerunit 305 contacts surface 307 of fifth wheel 304).

Referring to FIG. 4, once the trailer unit 102 is in contact withsurface 224 and is therefore aligned, movement means in the form ofpneumatically controlled arms 226 are actuated to raise the cab unit 202in a vertically upwardly and substantially linear direction to engagewith the trailer unit 102.

As the cab unit 202 is raised, the annular protrusions 110, 112 and 114of the trailer unit (shown in greater detail in FIG. 2), dimensionedsuch that they are complementary to the annular channels 210, 212, 214(shown in greater detail in FIG. 3A) engage with said annular channels.

The annular channels are dimensioned such that they allow a small degreeof misalignment between the cab and trailer units to be accommodatedfor.

Axial alignment between the cab unit 202 and trailer unit 102 is aidedby the provision of a skirt (not shown for the purposes of clarity)provided on one of the free ends of the units around the couplingsurface. The interior walls of the skirt are typically tapered tofurther aid this alignment and guide the other coupling unit intoengagement therewith.

When engagement of the annular protrusions and channels is complete, thepneumatic services can be provided from the cab unit via passageway 218,as shown in FIG. 3, to the trailer unit. Sealing means in the form of‘O’ rings are located in grooves 223 of the annular channels 210, 212,214 such that pneumatic passageway 216 forms a continuous sealedpassageway with pneumatic passageway 118 on the trailer unit uponengagement. The annular channels act to distribute and supply pneumaticpressure from the cab unit to the trailer unit.

An advantage of the annular channel and protrusion arrangement is thatpneumatic supply between the units will occur at substantially allpossible angular configurations of the channels relative to theprotrusions, thereby requiring no further alignment mechanism betweenthe cab and trailer units. In addition, pneumatic services can besupplied between the cab and trailer units even if the cab and trailerunits are not fully aligned.

The electrical supply between the cab unit 202 and the trailer unit 102is provided upon engagement of trailer plug 116 with cab socket 206.

Referring to FIGS. 6A-6E, there is illustrated the cab electrical socket206 and the trailer electrical plug 116. The socket 206 has a housing250 which is located in the cab unit 202, and the housing and socket canbe rotatable relative to the cab unit.

The cab socket 206 is designed to accommodate misalignment between thesocket and trailer plug of approximately +/−5 degrees, by the provisionof fins 252 on socket 206.

The fins 252 are located on the exterior surface of housing 250 andengage with shaped slots 260 provided adjacent the end of trailer plug116, thereby allowing alignment of the socket and plug prior to anyelectrical connection being made.

The cab socket 206 is also provided with an integral protruding flange253 and a number of pin recesses 254 provided on engagement surface 256.An earth pin recess 258 is provided centrally of the housing 250.

As mentioned above, trailer plug 116 has shaped slots 260, which are ofcomplementary shape to socket fins 252. A plurality of electrical pins262 and an earth pin 263 are provided on engagement surface 265 oftrailer pin. The pins 262, 263 are recessed within the plug to preventdamage to the same when the trailer is disengaged from the cab.

In use, the fins 252 on the cab socket align with slots 260 on thetrailer plug. Once aligned the socket and plug are engaged and flange253 is located in slots 260 to prevent further movement of the socketrelative to the plug.

During normal articulation the electrical plug and socket connection canundergo some degree of rotation consistent with the rotation of the caband trailer units during articulation.

Since the electrical pins are fragile, it is possible to replace the pinand socket arrangement with a multiplex system, where the cab unitsupplies electrical pulses to the trailer unit. An example of such aconnection is shown in FIG. 6F, where a cab electrical plug 270 isprovided with a shaped end 272 for location in complementary shaped end274 of trailer electrical socket 276. One or more cables 278, 280 orother communication means can be provided in plug 270 and socket 276respectively to transmit the electrical pulses between the cab andtrailer. Black box technology provided in or adjacent the ends of plugand/or socket allow for the processing and decoding of said electricalsignals. Alternative forms of electrical connections can be provided,such as a fibre optic switching device and/or the like. This can bebased on a similar plug and socket arrangement as shown in FIG. 6F.Angular misalignment between the cab and trailer unit in any of theabove mentioned electrical embodiments are typically catered for by theshaped ends and do not require further alignment. In addition, the plugand socket arrangement can be significantly reduced in size compared tothe electrical pin embodiment.

A signal box can be provided in the cab to allow the driver to determinethe success of coupling between the trailer and the cab without actuallyhaving to leave the cab.

The signal box can provide audio and/or visual signals to the driver.For example, once electrical connection between the cab unit and trailerunit is made, a light can be lit or an alarm can be sounded to indicateto the driver that engagement of the units has taken place successfully.A series of audible or visual signals can be used for different stagesof the coupling or for signalling any problems which may arise duringcoupling.

Once coupling between the cab and trailer units has been made, thedriver can operate a primary locking mechanism, as shown in FIGS. 5A and5B in a closed and open position respectively. This can be actuated bythe depression of an electrical switch on a control panel or on thesignal box. Alternatively, the primary locking mechanism can be actuatedautomatically upon engagement of the cab and trailer units.

The primary locking mechanism includes a catch 302 which is rotatablymounted on the fifth wheel 304 of the cab. The fifth wheel 304 of thecab unit has a conventional trailer coupling unit location port 312. Thecab coupling unit 202 is provided beneath the location port 312 and isnot shown in FIGS. 5a & 5 b for clarity. Once trailer unit 305 islocated in location portion 312 and makes contacts with wall 307 and thecab unit is raised into engagement with trailer unit 305, the catch 302rotates, as shown by arrow 314, to capture the trailer unit.

The primary locking mechanism can be pneumatically operated viapneumatic cylinders 310 or operated by any other conventional means,such as manually.

A locking wedge 306 can be provided to prevent the primary lockingmechanism from disconnecting in the event of pneumatic failure oraccidental disconnection of the trailer unit from the cab unit whenmoving off following coupling of the units. The locking wedge 306 ismounted on an arm 316 also operated by pneumatic cylinders 310, and arm316 is moved across the location port 312 to wedge the catch in anengaged position and to prevent rotation thereof. As mentionedpreviously, activation and/or deactivation of the locking mechanisms canbe signalled to the driver via the signalling box.

A further safety locking mechanism 308 providing spring loadedengagement or other biasing means can be employed to prevent unlockingof the primary locking mechanism in the event of pneumatic failure.During the uncoupling procedure, an electrical solenoid is actuated tooperate the safety locking mechanism 308 and allow retraction of thelocking wedge 306.

The catch 302 and the biasing means of the safety locking mechanism 308are typically pivoted to allow for rotation of the same. Catch 302 isoperated by the action of the trailer coupling unit entering locationportion 312.

During the coupling procedure, cylinder 310 has unrestricted air flow toallow movement of arm 316 and thus movement of catch 302 and lockingwedge 306. Pneumatic cylinder 318 of catch 308, which can be directly orindirectly connected to arm 316 and spring biases arm 316 to a lockedposition, has restricted air flow. The uncoupling procedure is thereverse of the coupling procedure, with cylinder 318 of safety catch 308having unrestricted air flow and cylinder 310, operating arm 316, havingrestricted air flow.

Trailers are typically provided with jacks/support legs 402 to supportthe trailer 403 when in a parked position, as shown in FIG. 7. Once thetrailer and cab are coupled together the trailer jacks can be raised(shown by dotted line 404) and lowered 406 from within the cab using thesystem of the present invention, power being delivered by the supplylines of the present invention. For example, the jacks can be operatedvia a pneumatic cylinder 408. The jack is connected and movable via amulti linkage system 410.

A quick release mechanism can be provided such that upon engagement ofthe cab and trailer units, the jacks rise sequentially and so the caband trailer can be driven off almost immediately following coupling,thereby reducing the turnaround time of a lorry following loading orunloading.

Operation of the jacks from within the trailer is also important toensure that the trailer and cab are positioned at a suitable heightrelative to each other, such that when the trailer is being loaded andunloaded, the coupling efficiency is maximised.

FIGS. 8A and 8B show simplified views of the pneumatic supply 502according to an embodiment of the present invention, with the cab unit504, and pneumatic arm 505 (shown as 226 in FIG. 4) used to allow thecab unit 504 to be raised and lowered, shown prior to engagement withthe trailer unit 506. The pneumatic supply components 502 which may beused with the present invention can be retrofitted to conventional cabconnectors 508 or the components can replace conventional connectors.Similarly electrical components used with the present invention can beretrofitted to conventional electrical connectors, thereby allowing acab unit incorporating the present invention to tow a conventionaltrailer.

FIG. 8B shows the pneumatic valves which operate during coupling of thecab and trailer units. Closure of the isolation valves 512 upondecoupling of the cab and trailer isolate the pneumatic supply in thecab unit prior to disconnection of the pneumatic supplies between thecab and trailer units. Opening of the isolation valves during couplingactuates the pneumatic supply from the cab unit to the trailer unit.

Since the coupling efficiency is improved between the trailer and thecab using the present invention, the flexible coiled hoses typicallyfound on conventional trailer/cab units can be removed. Short armouredflexible hoses 510 can be used to provide the pneumatic supply to thecab unit, thereby increasing the strength and durability of the same.

The trailer and/or cab coupling units can be provided with waterproofcoverings to protect the same from the weather and debris which may flyup during transit.

The procedures described above can all be performed by the driverwithout having to leave the cab, thereby making the coupling systemaccording to the above invention both safer and easier to use thanconventional coupling methods.

What is claimed:
 1. A coupling system for a vehicle for coupling atleast a tractor unit to a trailer unit, said tractor unit having firstcoupling means which engage with complementary second coupling means onsaid trailer unit, said first and second coupling means having one ormore service supply lines provided therein and said service supply linesof said first and second coupling means engaging upon mechanicalengagement of said first and second coupling means, thereby allowing thesupply of services from said tractor unit to said trailer unit and/orvice versa, and characterised in that one of said first or secondcoupling means is provided with one or more annular protrusions on acoupling surface and the other of said coupling means is provided withcomplementary annular channels on a coupling surface, said annularprotrusions being received in said annular channels upon mechanicalengagement of said first and second coupling means, therebysimultaneously or substantially simultaneously allowing the connectionand/or communication of at least one of the tractor supply lines with atleast one of the trailer supply lines to allow the supply of saidservice(s) therebetween.
 2. A coupling system according to claim 1characterised in that said service supply lines provide at leastelectrical and/or pneumatic supply between the tractor and trailerunits.
 3. A coupling system according to claim 1 characterised in thatone or more pneumatic supply lines are connected or communicate uponreceipt of the annular protrusions in the annular channels.
 4. Acoupling system according to claim 3 characterised in that the one ormore pneumatic supply lines have openings in said annular channels andcorresponding openings on said annular protrusions.
 5. A coupling systemaccording to claim 3 characterised in that sealing means are provided insaid annular channels to allow a continuous sealed pneumatic passagewaybetween said tractor unit and said trailer units to be formed onengagement of said annular protrusions/channels.
 6. A coupling systemaccording to claim 2 characterised in that the electrical connection isachieved by engagement of a centrally located plug in one of saidcoupling means and a complementary centrally located socket in the otherof said coupling means.
 7. A coupling system according to claim 6characterised in that complementary engagement means are provided on thehousings of said plug and socket to allow mechanical engagement of theplug and socket prior to, or simultaneously to electrical connectionbetween said plug and socket.
 8. A coupling system according to claim 7characterised in that the engagement means includes one or more finportions on the housing of one of said plug or socket which engage withone or more complementary recess/slot portions provided in the housingof the other of said plug or socket.
 9. A coupling system according toclaim 6 characterised in that electrical connection of said electricalplug and socket when engaged is provided by electrical pulse signalsprovided by a multiplex system passing between said plug and socket. 10.A coupling system according to claim 6 characterised in that electricalconnection of said electrical plug and socket when engaged is providedby fibre optic means.
 11. A coupling system according to claim 6characterised in that the electrical plug includes one or moreprotruding pins which locate in one or more complementary pin recessesprovided in said electrical socket to allow electrical connectiontherebetween.
 12. A coupling system according to claim 1 characterisedin that one of the coupling means is provided with linearlyreciprocating means to allow motion between a coupled position whereinthe coupling means are engaged and an uncoupled position wherein thecoupling means are disengaged and spaced apart.
 13. A coupling systemaccording to claim 12 characterised in that the second coupling means ofthe trailer unit is aligned above the first coupling means of thetractor unit during the coupling procedure and said linearlyreciprocating means raises or lowers one of said coupling means betweenthe coupled and uncoupled positions.
 14. A coupling system according toclaim 12 characterised in that the linearly reciprocating means includesa pneumatically operated arm.
 15. A coupling system according to claim 1characterised in that locking means are provided to lock the first andsecond coupling means together when in a coupled position.
 16. Acoupling system according to claim 15 characterised in that the lockingmeans include a catch provided on one or both of said units.
 17. Acoupling system according to claim 16 characterised in that the catch isrotatably mounted to capture the first and/or second coupling means uponmechanical engagement thereof.
 18. A coupling system according to claim16 characterised in that the catch is provided on a fifth wheel of thecab unit and captures the coupling means of said trailer unit.
 19. Acoupling system according to claim 1 characterised in that a quickrelease switch is provided in one or both of said tractor and trailerunits to enable uncoupling thereof.
 20. A coupling system according toclaim 1 characterised in that the tractor and/or trailer unit isprovided with a signal box having audio and/or visual signal means toindicate to a user/driver of the unit(s) whether coupling of the tractorand trailer units has been completed successfully and/or unsuccessfully.21. A coupling system according to claim 20 characterised in that thesignal means includes one or more audible alarms.
 22. A coupling systemaccording to claim 20 characterised in that the signal means includes onor more light sources which are switched on/off and/or change colourwhen coupling has been completed successfully and/or unsuccessfully. 23.A coupling system according to claim 1 characterised in that thecoupling system is provided with security means to prevent unauthoriseduse of said coupling system.
 24. A coupling system according to claim 23characterised in that a pin number or authorisation code is required tobe entered into the security means before one or more functions of thecoupling system are operational.
 25. A coupling system according toclaim 23 characterised in that the security means is connected to thevehicle's starter motor and/or brake system.
 26. A coupling systemaccording to claim 2 characterised in that pneumatic hoses and/orelectricity cables providing the pneumatic supply and/or electricitysupply are short, armoured flexible hoses or cables.
 27. A couplingsystem according to claim 2 characterised in that connection of one ormore pneumatic supply lines between said trailer and tractor unitsallows the operation of one or more support legs on said units.
 28. Acoupling system according to claim 27 characterised in that the one ormore support legs are provided with locking means to lock the supportlegs in an in-use position, where the legs are in contact with a floorsurface, and an out-of-use position where the legs are out of contactwith a floor surface.
 29. A coupling system according to claim 20characterised in that signalling means in the first and/or second unitindicate to a user/driver that one or more support legs are in an in-useposition or an out of position.
 30. A coupling system according to claim1 characterised in that the first and/or second coupling means areprovided with a cover or covers mounted over the coupling surfacesthereof.
 31. A coupling system according to claim 30 characterised inthat the cover(s) is/are spring loaded.
 32. A vehicle having a couplingsystem for coupling a tractor unit to a trailer unit, said tractor unithaving first coupling means which engage with complementary secondcoupling means on said trailer unit, said first and second couplingmeans having one or more service supply lines provided therein and saidservice supply lines of said first and second coupling means engagingupon mechanical engagement of said first and second coupling means,thereby allowing the supply of services from said tractor unit to saidtrailer unit and/or vice versa, and characterised in that one of saidfirst or second coupling means is provided with one or more annularprotrusions on a coupling surface and the other of said coupling meansis provided with complementary annular channels on a coupling surface,said annular protrusions engaging with said annular channels uponmechanical engagement of said first and second coupling means, therebysimultaneously or substantially simultaneously allowing the connectionand/or communication of at least one of the tractor supply lines with atleast one of the trailer supply lines to allow the supply of saidservice(s) therebetween.
 33. A fifth wheel for a tractor unit, saidfifth wheel having first coupling means which engage with complementarysecond coupling means on a trailer unit, said first and second couplingmeans having one or more service supply lines provided therein and saidservice supply lines of said first and second coupling means engagingupon mechanical engagement of said first and second coupling means,thereby allowing the supply of services from said tractor unit to saidtrailer unit and/or vice versa, and characterised in that one of saidfirst or second coupling means is provided with one or more annularprotrusions on a coupling surface and the other of said coupling meansis provided with complementary annular channels on a coupling surface,said annular protrusions engaging with said annular channels uponmechanical engagement of said first and second coupling means, therebysimultaneously or substantially simultaneously allowing the connectionand/or communication of at least one of the tractor supply lines with atleast one of the trailer supply lines to allow the supply of saidservice(s) therebetween.
 34. A method of coupling tractor and trailerunits together, said method including the steps of positioning saidtractor and/or trailer units relative to each other to allow alignmentof first coupling means on said tractor unit with second coupling meanson said trailer unit, actuating movement means on one of said couplingmeans to allow linear movement of said one coupling means to the otherof said coupling means which is fixedly mounted to couple said meanstogether, and characterised that one of said first or second couplingmeans is provided with one or more annular protrusions on a couplingsurface and the other of said coupling means is provided withcomplementary annular channels on a coupling surface, said annularprotrusions engaging with said annular channels upon mechanicalengagement of said first and second coupling means, said engagement ofsaid annular protrusions and grooves affecting connection of at leastone service supply line between said tractor and trailer unitssimultaneously or substantially simultaneously to the mechanicalcoupling of the tractor and trailer units.